These logs are annoyingly not regular text logs, but not far off. Is there a way to use a third party tool for filebeat to parse logs? Or any suggestions as to how best to deal with a log that filebeat can't read natively?

Turns out I am an idiot, and actually Filebeat parses it nicely - I just couldn't read it on the command line.

That said, I wonder if there's a way to direct another application at Filebeat to read the log. I can't imagine many instances where this is necessary (especially on Linux) but I bet there are strangely formatted logs on Windows that would require a particular application to read. Are there any ways in which these could be ingested like this?

Or, from another angle, what if one wanted to ingest compressed logs without having to decompress them - ad-hoc ingestion from archived logs for example. I've needed to do this myself more than once.